Multiple sclerosis (MS) is an autoimmune disease with the autoimmune activity directed against central nervous system (CNS) antigens. MS is an inflammatory demyelinating disease of the CNS, which results in damage to the protective covering (myelin sheath) that surrounds nerve fibers in the brain and spinal cord, leading to the loss of the myelin sheathing around neuronal axons (demyelination), axonal loss, and the eventual death of neurons, oligodendrocytes and glial cells.
When the myelin sheath is damaged, nerve impulses slow or even stop, causing neurological problems. MS is characterized clinically by relapses and remissions, often leading to progressive physical impairment. The cause of MS is unknown; however, pathologic, genetic, and immunologic features have been identified which suggest that the disease has an autoimmune basis. Although the antigenic target in MS is believed to be confined within the CNS, a systemic immunoregulatory defect may be present. T cells that were reactive to myelin basic protein (MBP) were detected in the blood of MS patients. Circulating blood cells of MS patients were also primed for enhanced cytokine synthesis. Exaggerated mitogen-inducible cytokine synthesis by peripheral monocytes was measured during the weeks immediately preceding the onset of episodes of relapsing MS. Thus, the exaggerated production of tumor necrosis factor (TNF), interleukin-1 (IL-1), and interferon-γ by circulating blood cells may serve as a peripheral trigger or marker for the induction of demyelinating inflammation in the CNS.
An estimated 2,500,000 people in the world suffer from MS. It is one of the most common diseases of the CNS in young adults. MS is a chronic, progressing, disabling disease, which generally strikes its victims sometime after adolescence, with diagnosis generally made between 20 and 40 years of age, although onset may occur earlier. The disease is not directly hereditary, although genetic susceptibility plays a part in its development. MS is a complex disease with heterogeneous clinical, pathological and immunological phenotype.
There are currently some available therapies in the clinic for the treatment of MS. However, most of them show poor efficacy, especially, in individuals who suffer from progressive. Moreover, they also have several side-effects (Wagner and Goverman, 2015, F1000Research 4:517; Pérez-Cerdá et al., 2016, Mult Scler Demyelinating Disord 1:9).